A continuous-coordinate image reconstruction method for list-mode time-of-flight position emission tomography

We present a new formulation for reconstructing list-mode time-of-flight (TOF) positron emission tomography (PET) data onto the continuous-coordinate event space based on maximizing the likelihood function. With this formulation, the spatial resolution is not limited by the a priori choice of the image voxels. We derive an iterative reconstruction algorithm and propose a serial processor (SP) for practical use. This SP reconstruction may support concurrent imaging, which is a new feature for PET imaging. The SP reconstruction approach is examined by using computer-simulated TOF PET data having a 600 ps FWHM concidence time resolution. Preliminary results show that the proposed approach is very promising.